This note presents a method to tune the resonant frequency f0 of a rectangular microwave cavity. This is achieved using a liquid metal, GaInSn, to decrease the volume of the cavity. It is possible to shift f0 by filling the cavity with this alloy, in order to reduce the relative distance between the internal walls. The resulting modes have resonant frequencies in the range 7÷8GHz. The capability of the system of producing an Electron Paramagnetic Resonance (EPR) measurement has been tested by placing a 1 mm diameter Yttrium Iron Garnet (YIG) sphere inside the cavity, and producing a strong coupling between the cavity resonance and Kittel mode. This work shows the possibility to tune a resonant system in the GHz range, which can be useful for several applications.
@article{arxiv.1804.03443,
title = {Microwave cavity tuned with liquid metal and its application to Electron Paramagnetic Resonance},
author = {C. S. Gallo and E. Berto and C. Braggio and F. Calaon and G. Carugno and N. Crescini and A. Ortolan and G. Ruoso and M. Tessaro},
journal= {arXiv preprint arXiv:1804.03443},
year = {2018}
}